code: def __getitem__(self, key):
      return self.children[key]
  
file_path: pytorch-metric-learning/src/pytorch_metric_learning/utils/key_checker.py
imports: from .None import common_functions
label_desc: Use image node_id 2 for calling the KeyCheckerDict obj's underlying member method code with example usage: obj.__getitem__(key) and returns: self